5.-CONCLUSIONS
The results presented in this work have evidenced the beneficious effect of antiapoptotic gene BHRF1 in hybridoma cultures in terms of cell growth, mAb productivity and metabolism; characterized by a more efficient usage of nutrients, doubling the cell density in culture under identical conditions and same culture media. The specific productivity of the cells has been multiplied by two, obtaining three times increase of final IgG3 concentration.
The study and comparison of the intracellular fluxes by means of the Flux Balance Analysis of the KB26.5 and KB26.5-BHRF1 engineered cell lines has enlightened the interactions and effects of BHRF1 protein on the metabolic pathways. In short, BHRF1 primarily affected glucose uptake rate, reducing glycolysis by 50% and consequently reducing the lactate generation by more than 60%. Interestingly, the total ATP generation in the engineered KB26.5-BHRF1 cell line has been significantly decreased due to the lower energy requirements for maintenance, probably due to the lower energy requirements for maintaining ion gradients, although this hypothesis should be evaluated with further metabolic flux analysis experiments.
The use of antiapoptotic genes has been extensively explored in the last years, as manifested in a very recent review about the attenuation of apoptosis in CHO cell line (Henry et al., 2020). Many efforts have been displayed to understand how these genes affect cell apoptosis; but the impact of those in protein production and specially in metabolism have not been completely understood by the scientific community. To tackle this issue, a strategy to obtain the isogenic cell lines should be implemented as it would allow the comparison between different anti-apoptotic genes and their effect.